The city of Boston marked a year since the deadly marathon bombings with a memorial ceremony.

Vice President Joe Biden was on hand for the ceremony at the Hynes Convention Center. He was joined by survivors and bystanders who then processed past the two bomb sites.

The family of 8-year-old Martin Richard, the youngest victim in the attacks, visited the wreaths placed on those two sites.

Paul Norden was near the finish line cheering on a friend when the explosions happened.

"Unfortunately, I looked to my right and I saw my leg on the ground," he said.

Norden's brother, JP, said he also felt the blast but did not know he had suffered the same injury.

"The bomb goes off, and I'm on the ground, and I was confused," JP Norden said. "I don't know why but I was confused. I thought I got punched or something. But then people started rushing over, and putting me down, they start doing tourniquets. And they're like 'relax, relax, relax.'"

That day was the start of dozens of surgeries and months of rehabilitation for the brothers. A year later, they're both walking again thanks to $140,000 prosthetics.

"Things happen in life, unfortunately, that you don't have answers to," the brothers said. "It is what it is. You know, you just got to get by it. I just keep moving forward."

The Nordens said that while they'll be forever linked to that horrific event, it by no means defines them.

Family and friends said they would be walking the entire marathon route to raise money so both brothers can have the prosthetic legs they need for the rest of their lives.